Bottoms for metallurgical furnaces of the bessemer converter type



April 8, 1958 H. KOSMIDER ETAL 2,829,879 IBOTTOMS FOR METALLURGICALFURNACES OF THE BESSEMER CONVERTER TYPE Original Filed Feb. 10, 1950Invenldr:

HANS KOSM/DER 6 PAUL ERNST HARDT M, G/ww-ne JMI-Z" A Home United StatesPatent Ofifice BOTTOMS FOR METALLURGICAL FURNACES OF THE BESSEMERCONVERTER TYPE Hans Kosmider and Paul Ernst Hardt, Hagen-Haspe, Germany,assignors to Huettenwerk Haspe Aktiengesellschaft, Hagen-Haspe, Germany,a German company Continuation of application Serial No.'143,602,

10, 1950. This application June 439,392

February 25, 1954, Serial No.

4 Claims. (Cl. 266-35) ent application.

In the converter process) the refining gases (air, oxygen,

friction in the individual tuyeres is too great, the tuyeres begin toburn away in the shape of funnels and this leads to a progressive wearand tear of the tuyere outlet. burning away is to be attributed not onlyto thermal overheating but above all to the chemical influence of theferrous oxide.

Ferrous oxide is a very powerful liquefying agent for all basic and acidrefractory materials. In the blast refining process the tuyeres and thusthe floor or bottom are extensively protected by the carrier ent in thebasic process. The ferrous oxide concentration and temperatureimmediately above the nozzle thus becomes greater. With increasingtemperature and ferrous oxide concentration the destruction of thetuyeres both in basic and acid bottoms is accelerated. As experimentshave shown the tuyeres burn to funnel shaped holes even after only oneor two charges. The emergent cross section becomes continuously greaterand the escape velocity of the refining gas continuously less. The ironto be refined can always penetrate deeper into the widened (burnt out)tuyeres, and the ferrous oxide can therefore react more with the basicand acid refractory substances. The funnel shaped end deep burning outleads then to destruction of the bottom. With the use of oxygen andother gaseous or solid refining means, tuyeres and bottoms of usualconstruction made of basic or acid refractory material can no longer beeconomically used.

The present invention is directed to the problem of preventing or atleast substantially lessening this funneling out or cratering of thefurnace bottom in the vicinity of the tuyeres. As explained above, suchcratering occurs particularly with an oxygen-enriched blast, and alsowith pure oxygen or a mixture of pure oxygen and other refining agents.

It has been proposed in the past to form the tuyeres of 2,829,879Patented Apr. 8, 1958 iron tubes primarily to achieve better heatconductivity. However, the use of iron The damging effects of thismaterial are fully discussed abo e. Consequently, although it has beenthe blast nozzles or tuyeres, this practice has not to our knowledgebeen used to any substantial extent. In fact, it is obvious that withhigher oxygen content blasts, the iron tubes will actually increase theformation of ferrous oxide.

,We have discovered that, despite its lower melting point, copper may beused to provide the blast nozzle arising in the refining processdirectly over the nozzles does not combine with the copper protectivetubes of the single tuyeres. Furthermore, the ferrous oxide cannot reacteither directly or indirectly with the refractory material from theinner side of the nozzles.

iron. According to our invention, the blast nozzle tubes or tuyeres mayconsist of copper or a copper alloy which has an oxygen aflinity andheat conductivity substantially similar to copper.

Referring to the single figure of the drawing, there is shown there across-section in elevation of a furnace bottom of the Bessemer convertertype. In place of the usual wooden tubes or needlesas they are sometimecalled, there are a plurality of copper tubes 1 which are embedded inthe refractory crushed material 2. As indicated by the legend on thedrawing, this refractory material 2 may be either acid or basicrefractory and the tubes I extend completely through it as shown in thedrawing. Furthermore, the furnace bottom includes a base plate 3containing openings as shown in the drawing and the tubes I extend fromthese openings, through the refractory material, to the interior of thefurnace. In fact the copper tubes 1 can be placed into the bottom plate3 in the same manner as the wooden rods or needles used. In other words,the over-all construction of the usual furnace bottom is not changed.According to the present invention copper tubes are used instead of theusual wooden rods or needles. Thus the present invention is animprovement upon furnace bottoms of the type conventionally used.

By using smooth metal tubes of copper, the frictional resistancecompared with that of the rough surface of tuyeres formed in therefractory material directly is substantially smaller, and thus theenergy consumed in supplying the refining agent is smaller. The tubes 1need not have a large wall thickness. In fact, the most preferablethickness of the wall of the copper tubes is in the range of l to 1.5mm. In effect, each tube is a liner for the blast passage with which itis associated.

While we have described and illustrated an embodiment of our invention,we wish it to be understood that we do not intend to be restrictedsolely thereto but that we do intend to cover all modifications whichwould be apparent to one skilled in the art and which come within thespirit and scope of our invention. Thus, for example, we intend to covertubes made of metals which have an oxygen atfinity and heat conductivitysubstantially the same as that of copper.

What is claimed as our invention is:

l. A bottom for a metallurgical furnace of the Bessemer converter type,said bottom comprising a mass of refractory material which occupies amajor portion of the depth of said bottom, and a plurality of coppertubes embedded in said refractory material and extending completelythrough said refractory material to provide blast passages for saidfurnace, each of said tubes consisting of a single wall of copper, saidcopper tubes having a smaller oxygen affinity than iron and very highheat conductivity whereby cratering of the refractory material in thevicinity of the tubes is substantially lessened and it is unnecessary towater cool the tubes.

2. A bottom for a metallurgical furnace of the Bessemer converter type,said bottom comprising a mass of refractory material which occupies amajor portion of the depth of said bottom, and a plurality of tubes madeof a copper alloy which has an oxygen aflinity and heat conductivitysubstantially similar to copper, said tubes being embedded in saidrefractory material and extending completely through said refractorymaterial to provide blast passages for said furnace, each of said tubesconsisting of a single wall of said copper alloy. said copper alloytubes having a smaller oxygen aifinity than iron and very high heatconductivity whereby cratering of the refractory material in thevicinity of the tubes is substantially lessened and it is unnecessary towater cool said tubes.

3. A bottom for a metallurgical furnace of the Bessemer converter type,said bottom comprising a mass of refractory material which extendssubstantially entirely throughout the depth of said bottom, saidrefractory material having a plurality of substantially v ertical blastpassages extending completely through said material from top to bottom,a single copper tube which extends substanti throughout the length ofthe passage with associated and which from i to 1.5 millimeters.

each of said passages being lined by only ally entirely which it is 4. Abottom for a metallurgical furnace of mer converter type, said has awall thickness in the range the Bessebottom comprising a mass ofrefractory material which extends substantially entirely throughout thedepth of said bottom,

said refractory material having a plurality of substantially verticalblast passages extending completely through said refractory materialfrom top to bottom, being lined by only a single each of said blastpassages tube made of a copper alloy which has an oxygen affinity andheat conductivity substantially similar to copper, each tube extendingsubstantially entirely throughout the length of the passage with whichit is associated and having a wall thickness in the range from 1 to 1.5millimeters.

References Cited in the file of this patent FOREIGN PATENTS 9,3 54Germany OTHER REFERENCES Apr. 6, 1880 page 49 relied on.

0804, July

1. A BOTTOM FOR A METULLURGICAL FURNACE OF THE BESSEMER CONVERTER TYPE,SAID BOTTOM COMPRISING A MASS OF REFRACTORY MATERIAL WHICH OCCUPIES AMAJOR PORTION OF THE DEPTH OF SAID BOTTOM, AND A PLURALITY OF COPPERTUBES EMBEDDED IN SAID REFRACTORY MATERIAL AND EXTENDING COMPLETELYTHROUGH SAID REFRACTORY MATERIAL TO PROVIDE BLAST PASSAGES FOR SAIDFURNACE, EACH OF SAID TUBES CONSISTING OF A SINGLE WALL OF COPPER, SAIDCOPPER TUBES HAVING A SMALLER OXYGEN AFFINITY THAN IRON AND VERY HIGHHEAT CONDUCTIVITY WHEREBY CRATERING OF THE REFRACTORY MATERIAL IN THEVICINITY OF THE TUBES IS SUBSTANTIALLY LESSENED AND IT IS UNNECESSARY TOWATER COOL THE TUBES.